1. Field
Embodiments of the present invention relate to methods and systems for manufacturing aircraft parts. More particularly, the invention relates to methods and systems for manufacturing a honeycomb core structure.
2. Related Art
Honeycomb cores are often used to strengthen aircraft parts. Particularly, honeycomb cores are often incorporated into aircraft parts in such a way as to provide a sufficiently strong load path for heavy components of the aircraft and/or components of the aircraft which experience high compression and shear forces.
In some applications, such as an engine nacelle or other applications requiring sound absorption, a double layer of honeycomb core is used, with a septum bonded between the two layers. This construction requires a multi-step process of first forming and hardening the honeycomb core, then bonding the two layers to the septum. It is difficult to precisely align the individual cells of the adjacent honeycomb layers. Furthermore, the bond lines between the septum and the honeycomb core degrade the strength of the sandwich structure.
Other types of honeycomb cores with acoustic septum press a single, pre-formed honeycomb core layer into a layer of liquid resin septum and an adjacent layer of wax-like material. The wax melts away and the liquid resin septum cools and hardens such that it bonds to cell walls of the honeycomb cores. This method overcomes the need to align individual cells of two honeycomb layers, and also eliminates the bond lines which can degrade the strength of the sandwich structure. However, this method still requires a two-step process in which the honeycomb core is first formed and hardened. Once the honeycomb is hardened, it is then joined with the septum, which is subsequently hardened against the hardened honeycomb cell walls. These two separate processes for first making the honeycomb core and then joining it with the septum can each be time- and labor-consuming and require separate tooling.
Accordingly, there is a need for an improved method of manufacturing a honeycomb core with an acoustic septum that does not suffer from the deficiencies of the prior art.